Electric vehicle drive through double gearing



Oct. 8, 1929. J. wERz v V1,730,989

ELECTRIC VEHICLE DRIVE THROUGH DOUBLE GEARING Filed Deo. 14. 1926 2 Sheets-Sheet l l oct. s, 1929. I J. WER; A 1,130,989

ELECTRIC VEHICLE DRIVE THROUGH DOUBLE 'Gamma Filed Dec. 14. 19257 2 sheets-sneer 2 Patented Oct. 8, 1929 Unirse sra'res PATENT OFFICE JACOB WERZ, 0F GENEVA, SWITZERLAND, ,ASSIGNOR T0 SOCIETE ANONYME DES ATELIERS DE SECHERON, OF SECHERON, SWITZERLAND, A CORPORATION OF SWITZERLAND ELECTRIC VEHICLE DRIVE THROUGH DOUBLE GEARING Applcation'Ied December 14, 1926, Serial No. 154,740, and in Germany January 13, 1926.

This invention relates to improvements in electric drives for vehicles with double gearing, in which the motor is supported on the driving axle on bracket bearings and is also suspended to the car trame.

According to the invention, the electric vehicle drive is characterized bythe axis et the driving' motor lyinr'in the direction oiZ the longitudinal axis ot the vehicle; by the gearing which is next to the motor being,Y constituted by a bevel `gear and linally by the gearing' next to the driving` axle, beingv constituted by one or more spur wheel gears, 'for the purpose of obtaining` the highest possible gear ratio, not limited by the motor diameter. with the least amount of space required. by the gearing in the direction of the longitudinal axis of the vehicle.

Two constructions ot the electric drive aecording to the invention are illustrated by way et examples in the' accompanying' drawing; in which:

Figure 1 is a vertical longitudinal sectie and l F ieure 2 a plan, partly in section ot a first construction. y

Figure 3 is a side elevation and Figure et a top view partly in section of the second construction.

rlhe electric motor a according' to Figs. 1 and 2, is so arranged that its horizontal axis a' is parallel to the longitudinal axis jl/ of the vehicle and above the driving axle g. It rests on two bearings 7a on the said driving axle g and is connect-ed to the car trame Z by springs s. It drives a countershaft supported in bearings c' in the motor casing, through a bevel Z), c, the pinion Z) of which is keyed to its shaft The countersha'ft d drives thedriving axle g through two symmetrical spur wh eels e, f, of which. the pinions e are mounted onk the counter-shaft (l.

As the motor a is mounted on bearings 7L on. the driving; axle g, and the countershaft d is mounted on the motor e, a proper meshing both of the bevel wheels and of the spur wheels is ensured.

lviotor sets with double .gearing hitherto used i'or electrically propelled vehicles, have parallel motor shafts and driving axles. Vilhen usino; small driving wheels, which is highly7 desirable for providing' a low boarding platform, Yfor instance in tram vehicles, it is not always possible, even when using double rgearing, to obtain the high gear ratio required tor ythe proper utilization of the motor, as the axle gear wheel may be made only large as is allowed by railway regulations with regard to the clearance from the top of the rail.

It results from the geometry of toothed wheel `sears, that in the arrangements hitherto used, the greatest possible gear ratio for a given driving wheel diameter and for a given speed ot' travel, can be the greater the smaller the diameter ot the motor, that is to say the Lgear ratio depends on the external diameter of the motor. This dependence of the gear ratio on the diameter ot the Inotor is due to the fact that in the usual arrangement, the countershatt is outside the motor casing. As-y suming a certain thickness oit` the axle, the distance between the centres oi the motor and counter shaft may be determined, andagain assuming the `greatestpossible diameter of the wheel, also the diameter ofthe pinion, and therefore the ratio may be determined.

It is now obvious from the drawing that the ,gear ratio is independent of the diameter e ot the motor, and that'the gearing takes up little space in the longitudinal direction of the vehicle, which is more particularly of great importance in the case ol bogie trucks on account of the usually small wheel base.

Further is the space room occupied by the drive on both sides of the 'driving axle as small as possible.

As already stated, the motor e is suspended on springs on the car frame at 7c, and its supportant the driving; axle f! 1""CL .Any

shocks transmitted from the track m to the driving wheels a therefore are not only telt on the motor casing, but also cause a relative turning of the motor about its point ot sup- `port on the driving axle g. rlhis results however in a turning or" the countershatt d and ot the motor shaft t, as the gear wheels lieyed to the driving axle g mesh with the pinions e. A rolling ot the pinions e on the gear Wheels f must therefore necessarily talie place. rEhese shocks producing a. variation ot' the angular velocity, are absorbed by a spring coupling act-ing in the circumferential direction. The large wheel c ot the bevel gear Z), c, is mounted on the countershatt Z so tha' it can rotate to a certain angle, and connected by springs fr to a driver abutment g secured to the countershaft d.

rllhe bevel wheels can be replaced by helical wheels.

The spur gearing between the driving axl g and the countershatt Z may be on one side only.

The damping spring coupling r, g can be replaced by a slip clutch or some other suitable device which can be mounted at any desired point between the motor shattand the driving axle.

The axis ot the motor may also be in the `plane which contains the geometrical axis ot the driving axle or below this plane: it may be inclined with reference to said plane.

ylhe countershatt ot the spur wheels may be provided with a braking device; in this manner a good braking eltect may be obtained: lt the wheels o the driving axle are acted upon tor the braking, the braking effect is not always the wanted one on account ci the form, the wear and the dirtiness ot the rolling surfaces of said wheels; in the case the motor shaft is acted upon, the braking edect is also not a good one, as said shaft too rapidly rotates.

ln accordance with Figs. 3 and e the braking device is arranged as follows: Il drum u is keyed on the countershatt CZ which is pro vided with one spur wheel e only; with said drum u one brake, member o engages in order to obtainthe braking efect on the driving axle g.

The braking device may be a mechanical, a pneumatic, an electrical one. lt may be provided at anyplace and also at both ends ot the countershatt (Z. lt may be arranged as an inner or outer brake.

l claim:

l. ln an electric vehicle drive the combination, with a motor resting on bracketbearings on the driving axle and suspended to the car trame, ot the axis of the driving motor being arranged in the direction ol' the longitudinal axis ot the vehicle, a double gear between the motor and the driving axle, the gearing y situated next to the motor being constituted by a bevel gear and the gearing next to the drivine' axle being constituted by one spur wheel, means being provided tor absorbing the shocks transmitted trom the driving axle through the gearing to the motor sha't't.

2. ln an electric vehicle drive the combination, with motor resting on bracket bearings on the driving axle and suspended to the car trame, or" the axis of the driving motor sing arrangedin the direction of the longitudinal axis Ot the vehicle, a double gear between the motor and the driving axle, the gearing situated next to the motor being constituted by a bevel gear and the gearing next to the driving axle being constituted by one spur wheel, a device being provided for braking the countershaft on which the spurwheel is seated.

3. ln an electric vehicle drive the combination, witn a motor resting on bracket bearings on the driving axle and suspended to the car traine, or" t e axis ot the driving motor beine' arranged in the direction ot the longitudinal axis ot the vehicle, a double gear between the motor and the driving axle, the gearing situated next to the motor being constituted by a bevel gear and the gearing next to the driving axle being constituted by one spur wheel and being located with reterence to the driving axle on the side opposite to that on which the motor is situated.

e. In an electric vehicle drive the combination, with a motor resting on bracket bearings on the driving axle and suspended to the car traine, ot the axis of the drivin@ Inotor being arranged in the direction or the longitudinal axis or" the vehicle and above the driving axle, a double gear between the motor and the driving axle,`the gearing situated next to the motor being constituted by a bevel gear and the gearing next to the driving` axle being constituted by one spur wheel tor the `purpose ot obtaining the highest possible gear rationot limited by the motor diaineter and requiring the smallest possible space tor the gearing in the direction ot the longitudinal axis of the vehicle.

5. in an electrical vehicle drive, a drive shalt, a motor mounted in a trame journaled at one end on the drive shaft and yieldingly iounted at the other end in the vehicle frame, the axis ot the motor being arranged in the direction ot the longitudinal axis ot the vehicle with the motor at one side ot the drive shaft, a counter shaft journaled in bearings in the motor traine at the other side ot the drive shaft, beveled gears connecting the motor shalt and the counter shaft, and spur gears connecting the counter shaft and the drive shaft.

6. ln an electric vehicle drive, adrive shatt, a motor mounted in aftrame journaled at one end on the drive shaft and yieldingly mounted at the other end in the vehicle trame, the axis ot the motor being arranged in the direction of the longitudinal axis ot the vehicle, a counter shaft journaled in signature.

JACOB WERZ. 

